Steganography

Steganography

For hundreds of years, man has struggled to provide constant security. Steganography and cryptography is intertwined with one another, but these two methods each have strengths and weaknesses. The aim is not to go into detail, but to provide details of what goes into steganography.  Steganography derives from a Greek word “steganographia” which means covered writing.  Steganography is the art and science of communicating in a way which hides the true meaning of the communication.  The goal of steganography is to hide messages inside other harmless messages in a way that does not allow anyone to detect that there is a second secret message present.  Steganography was also used during ancient times.  One way of sending messages was to cloak them in images. The art of Steganography originated from a Greek man named Histiaeus, who was a prisoner of a rival king. He needed a way of transmitting a secret message to his people. He had the idea of shaving a willing slaves head and tattooing the message onto his scalp. When the slave's hair grew back, he was sent to deliver the message to Histiaeus' army [1] Along with steganography, comes cryptology.  Cryptology derives from the Greek words kryptos meaning hidden and logos meaning word.   The messages often delivered were not only hidden but also cryptic for added security measure.  During the middle ages sending hidden and cryptic messages were used by basically substituting different letters of the alphabets with letters.  The messages became more complex and cryptic as time went on and steganography started to become a science.  It was often used by royalty for sending messages to different kingdoms and also became useful during wars.  These hidden messages were also incorporated in artwork.  Johannes Trithemius, German Monk and Scholar found a way of delivering messages that didn’t need books or messengers.  Trithemius published a book and by all accounts was thought to be a book about the occult.  This book was also banned by the Catholic Church.  “But almost 500 years after Trithemius set down his pen, a German professor at La Roche College, Thomas Ernst, has unlocked his secret. Trithemius, it seems, has had a good long laugh.  This was no astrological treatise. Rather, what modern occultists continue to regard as a black-magic manual was an exercise in encryption, employing a cipher system that substituted numerals for letters.  All of Trithemius' references to otherworldly spirits and instructions on making talismans "was a very effective smokescreen," Ernst said, that provided an excuse to include long tables of numbers. Trithemius was no magician, but he was a master illusionist.” [2] Steganography is also based on the idea of security through obscurity.  If nobody knows there's a hidden file, why should anyone want it? With all the internet traffic and the number of attachments that are downloaded or shared via email, there is not computing resources to scan all transfers of images, sounds and other files that are being transmitted. However, some companies actively monitor all attachments passing through their network just to verify that hidden messages and specially trade secrets are being passed on.  This will be covered later on in the paper.